/**
 * Copyright (c) 2005-2010 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * 
 * $Id: ReflectionUtils.java 1211 2010-09-10 16:20:45Z calvinxiu $
 */
package org.mozhu.mboot.core.util;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.time.DateUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.Assert;

import java.lang.reflect.*;
import java.text.ParseException;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Date;

/**
 * 反射工具类.
 * 
 * 提供访问私有变量,获取泛型类型Class, 提取集合中元素的属性, 转换字符串到对象等Util函数.
 * 
 * @author calvin
 */
@SuppressWarnings({ "unchecked", "rawtypes" })
public class ReflectionUtils {

	private static Logger logger = LoggerFactory.getLogger(ReflectionUtils.class);

	/**
	 * 调用Getter方法.
	 */
	public static Object invokeGetterMethod(Object obj, String propertyName) {
		String getterMethodName = "get" + StringUtils.capitalize(propertyName);
		return invokeMethod(obj, getterMethodName, new Class[] {}, new Object[] {});
	}

	/**
	 * 调用Setter方法.使用value的Class来查找Setter方法.
	 */
	public static void invokeSetterMethod(Object obj, String propertyName, Object value) {
		invokeSetterMethod(obj, propertyName, value, null);
	}

	/**
	 * 调用Setter方法.
	 * 
	 * @param propertyType
	 *            用于查找Setter方法,为空时使用value的Class替代.
	 */
	public static void invokeSetterMethod(Object obj, String propertyName, Object value, Class<?> propertyType) {
		Class<?> type = propertyType != null ? propertyType : value.getClass();
		String setterMethodName = "set" + StringUtils.capitalize(propertyName);
		invokeMethod(obj, setterMethodName, new Class[] { type }, new Object[] { value });
	}

	/**
	 * 直接读取对象属性值, 无视private/protected修饰符, 不经过getter函数.
	 */
	public static Object getFieldValue(final Object obj, final String fieldName) {
		Field field = getAccessibleField(obj, fieldName);

		if (field == null) {
			throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
		}

		Object result = null;
		try {
			result = field.get(obj);
		} catch (IllegalAccessException e) {
			logger.error("不可能抛出的异常{}", e.getMessage());
		}
		return result;
	}

	/**
	 * 直接设置对象属性值, 无视private/protected修饰符, 不经过setter函数.
	 */
	public static void setFieldValue(final Object obj, final String fieldName, final Object value) {
		Field field = getAccessibleField(obj, fieldName);

		if (field == null) {
			throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
		}

		try {
			field.set(obj, value);
		} catch (IllegalAccessException e) {
			logger.error("不可能抛出的异常:{}", e.getMessage());
		}
	}

	/**
	 * 循环向上转型, 获取对象的DeclaredField, 并强制设置为可访问.
	 * 
	 * 如向上转型到Object仍无法找到, 返回null.
	 */
	public static Field getAccessibleField(final Object obj, final String fieldName) {
		Assert.notNull(obj, "object不能为空");
		Assert.hasText(fieldName, "fieldName");
		for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
			try {
				Field field = superClass.getDeclaredField(fieldName);
				field.setAccessible(true);
				return field;
			} catch (NoSuchFieldException e) {// NOSONAR
				// Field不在当前类定义,继续向上转型
			}
		}
		return null;
	}

	/**
	 * 直接调用对象方法, 无视private/protected修饰符. 用于一次性调用的情况.
	 */
	public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes, final Object[] args) {
		Method method = getAccessibleMethod(obj, methodName, parameterTypes);
		if (method == null) {
			throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
		}

		try {
			return method.invoke(obj, args);
		} catch (Exception e) {
			throw convertReflectionExceptionToUnchecked(e);
		}
	}

	/**
	 * 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问. 如向上转型到Object仍无法找到, 返回null.
	 * 
	 * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object...
	 * args)
	 */
	public static Method getAccessibleMethod(final Object obj, final String methodName, final Class<?>... parameterTypes) {
		Assert.notNull(obj, "object不能为空");

		for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
			try {
				Method method = superClass.getDeclaredMethod(methodName, parameterTypes);

				method.setAccessible(true);

				return method;

			} catch (NoSuchMethodException e) {// NOSONAR
				// Method不在当前类定义,继续向上转型
			}
		}
		return null;
	}

	/**
	 * 通过反射, 获得Class定义中声明的父类的泛型参数的类型. 如无法找到, 返回Object.class. eg. public UserDao
	 * extends HibernateDao<User>
	 * 
	 * @param clazz
	 *            The class to introspect
	 * @return the first generic declaration, or Object.class if cannot be
	 *         determined
	 */
	public static <T> Class<T> getSuperClassGenricType(final Class<T> clazz) {
		return getSuperClassGenricType(clazz, 0);
	}

	/**
	 * 通过反射, 获得Class定义中声明的父类的泛型参数的类型. 如无法找到, 返回Object.class.
	 * 
	 * 如public UserDao extends HibernateDao<User,Long>
	 * 
	 * @param clazz
	 *            clazz The class to introspect
	 * @param index
	 *            the Index of the generic ddeclaration,start from 0.
	 * @return the index generic declaration, or Object.class if cannot be
	 *         determined
	 */
	public static Class getSuperClassGenricType(final Class clazz, final int index) {

		Type genType = clazz.getGenericSuperclass();

		if (!(genType instanceof ParameterizedType)) {
			logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");
			return Object.class;
		}

		Type[] params = ((ParameterizedType) genType).getActualTypeArguments();

		if (index >= params.length || index < 0) {
			logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: " + params.length);
			return Object.class;
		}
		if (!(params[index] instanceof Class)) {
			logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");
			return Object.class;
		}

		return (Class) params[index];
	}

	/**
	 * 将反射时的checked exception转换为unchecked exception.
	 */
	public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {
		if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException || e instanceof NoSuchMethodException) {
			return new IllegalArgumentException("Reflection Exception.", e);
		} else if (e instanceof InvocationTargetException) {
			return new RuntimeException("Reflection Exception.", ((InvocationTargetException) e).getTargetException());
		} else if (e instanceof RuntimeException) {
			return (RuntimeException) e;
		}
		return new RuntimeException("Unexpected Checked Exception.", e);
	}

	/**
	 * 得到指定类型的指定位置的泛型实参
	 * 
	 * @param clazz
	 * @param index
	 * @param <T>
	 * @return
	 */
	public static <T> Class<T> findParameterizedType(Class<?> clazz, int index) {
		Type parameterizedType = clazz.getGenericSuperclass();
		// CGLUB subclass target object(泛型在父类上)
		if (!(parameterizedType instanceof ParameterizedType)) {
			parameterizedType = clazz.getSuperclass().getGenericSuperclass();
		}
		if (!(parameterizedType instanceof ParameterizedType)) {
			return null;
		}
		Type[] actualTypeArguments = ((ParameterizedType) parameterizedType).getActualTypeArguments();
		if (actualTypeArguments == null || actualTypeArguments.length == 0) {
			return null;
		}
		return (Class<T>) actualTypeArguments[0];
	}

	public static Class<?> getFieldType(Class<?> entityClass, String propertyName) {
		Assert.hasText(propertyName, "propertyName不能为空");
		Class<?> propertyType = null;
		try {
			if (StringUtils.contains(propertyName, ".")) {
				for (String str : propertyName.split("\\.")) {
					Field declaredField = getDeclaredField(entityClass, str);
					entityClass = declaredField.getType();
				}
				propertyType = entityClass;
			} else {
				propertyType = getDeclaredField(entityClass, propertyName).getType();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		return propertyType;
	}

	/**
	 * 获取当前类的public字段
	 * 
	 * @param entityClass
	 * @param propertyName
	 * @return
	 * @throws SecurityException
	 * @throws NoSuchFieldException
	 */
	public static Field getField(Class<?> entityClass, String propertyName) throws SecurityException, NoSuchFieldException {
		return entityClass.getField(propertyName);
	}

	/**
	 * 获取当前类的所有字段，包括private,以及父类的所有字段
	 * 
	 * @param entityClass
	 * @param propertyName
	 * @return
	 */
	public static Field getDeclaredField(Class<?> entityClass, String propertyName) {
		Exception lastException = null;
		for (Class clazz = entityClass; clazz != Object.class; clazz = clazz.getSuperclass()) {
			try {
				return clazz.getDeclaredField(propertyName);
			} catch (Exception e) {
				lastException = e;
			}
		}
		throw new IllegalStateException("Cann't find any field [" + propertyName + "] in class [" + entityClass + "] or its supper class", lastException);
	}

	public static Object convertValue(String value, Class clazzType) {
		Assert.notNull(value, "value不能为空");
		if (String.class.equals(clazzType)) {
			return value;
		}
		if (Date.class.equals(clazzType)) {
			try {
				return DateUtils.parseDate(value, new String[] { "yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss" });
			} catch (ParseException e) {
				throw new IllegalStateException("Parse Date[" + value + "] Failed, using pattern [yyyy-MM-dd], [yyyy-MM-dd HH:mm:ss]", e);
			}
		}
		if (LocalDate.class.equals(clazzType)) {
			try {
				return LocalDate.parse(value, DateTimeFormatter.ofPattern("yyyy-MM-dd"));
			} catch (DateTimeParseException e) {
				throw new IllegalStateException("Parse Date[" + value + "] Failed, using pattern [yyyy-MM-dd]", e);
			}
		}
		if (LocalDateTime.class.equals(clazzType)) {
			try {
				return LocalDateTime.parse(value, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
			} catch (DateTimeParseException e) {
				throw new IllegalStateException("Parse Date[" + value + "] Failed, using pattern [yyyy-MM-dd HH:mm:ss]", e);
			}
		}
		if (clazzType.isEnum()) {
			return Enum.valueOf(clazzType, value);
		}
		if ("byte".equals(clazzType.getName())) {
			return Byte.valueOf(value);
		}
		if ("short".equals(clazzType.getName())) {
			return Short.valueOf(value);
		}
		if ("char".equals(clazzType.getName()) || Character.class.equals(clazzType)) {
			if (value.length() != 1) {
				throw new IllegalStateException("value length != 1, can't be converted to char");
			}
			return value.charAt(0);
		}
		if ("int".equals(clazzType.getName())) {
			return Integer.valueOf(value);
		}
		if ("long".equals(clazzType.getName())) {
			return Long.valueOf(value);
		}
		if ("double".equals(clazzType.getName())) {
			return Double.valueOf(value);
		}
		if ("float".equals(clazzType.getName())) {
			return Float.valueOf(value);
		}
		if ("boolean".equals(clazzType.getName())) {
			return Boolean.valueOf(value);
		}
		try {
			return getConstructorHasOnlyOneArg(clazzType).newInstance(value);
		} catch (Exception e) {
			try {
				return getValueOfMethod(clazzType).invoke(clazzType, value);
			} catch (Exception e1) {
				throw new IllegalStateException("Convert value by Constructor and ValueOf method failed!", e);
			}
		}
	}

	public static Object convertValue(String value, Class<?> entityClass, String propertyName) {
		return convertValue(value, getFieldType(entityClass, propertyName));
	}

	public static Constructor<?> getConstructorHasOnlyOneArg(Class clazzType) {
		try {
			return clazzType.getConstructor(String.class);
		} catch (Exception eStr) {
			logger.warn("get Constructor with String failed");
			try {
				Constructor<?> c = clazzType.getConstructor(Object.class);
				logger.warn("get Constructor with Object succeed");
				return c;
			} catch (Exception e) {
				throw new IllegalStateException("Constructor init failed!", e);
			}
		}
	}

	public static Method getValueOfMethod(Class clazzType) {
		try {
			return clazzType.getMethod("valueOf", String.class);
		} catch (Exception e) {
			logger.warn("get valueOf method with String failed");
			try {
				Method method = clazzType.getMethod("valueOf", Object.class);
				logger.warn("get valueOf method with Object succeed");
				return method;
			} catch (Exception e1) {
				throw new IllegalStateException("get valueOf method failed!", e);
			}
		}
	}

}
